Means for preventing reverse rotation of camera winding knobs



Nov. 5, 1940. J. GALTER 2,220,599

MEANS FOR PREVENTING REVERSE ROT ATION 0P CAMERA WINDING KNOBS Original Filed April 17, 1940 Patented Nov. 5, 1940 PATENT OFFICE MEANS'FOR. PREVENTING REVERSE ROTA- TION F CAMERA WINDING KNOBS Jack Galter, Chicago, Ill.

Original application April 17, 1940, Serial No. 330,130. Divided and this application August 8, 1940, Serial No. 351,876

3 Claims. (01.- 242-71) This is a divisional application of the original application on Turnable means for camera take up spools, Serial No. 330,130 filed April 17, 1940, now Patent No. 2,213,492 of September 3,

My invention relates to means for preventing rotation of the winding knob of a camera.

The object of my invention is to supply means for preventing the take up spool of a camera from being unwound, by a coiled spring on the shank operable with the walls of the casing itself and without the need of separate clutch inserts. My invention also contemplates such other objects, advantages and capabilities as will later more fully appear and which are inherently possessed by my invention.

While I have shown in the accompanying drawing a preferred embodiment of my invention, yet I wish it understood that the same is susceptible of modification and change without departing from the spirit of my invention.

Referring to the drawing, Fig. 1 is an elevational view of the interior of a camera from the rear showing my spring; Fig. 2 is a detail sectional view; Fig. 3 is an elevation of the preferred form of my brake spring; Fig. 4 is a detail sectional view; Fig. 5 is a perspective view of another embodiment of my spring construction. The embodiment selected to illustrate my invention comprises a camera in which there is a take up chamber it for housing the take up spool ii on which the exposed film is rolled. In orde: .o turn the take up spool ll from the ex- 35.teiior of the camera I provide a knob l2 having a shank '53 which extends through an opening it in the casing H into the take up chamber l0.

Suitable means may be provided for the en- 4 gagement of the shank 13 with the take up spool "ii.

A spring Si is coiled around the inner portion of the shank 13. The spring 9| 'the center of the spring. vWhen the shank 13 is inserted into opening 14 in casing ll, portion 92 of spring 9| enters slot 93 provided therefor in casing H adjoining opening 14. When the knob 12 is turned in the direction for winding film on the take up spool II, which is also arranged so that it is the unwinding direction for spring 9|, the wall of casing II to one side of the slot 93 acts as a clutch and grips portion 92. This permits relative rotation of spring 9| and shank 13. When the knob 12 is turned in at its outer end has a straight portion 92 on a radius from .the opposite direction, which is' also the direction for winding the spring 9|, portion 92 is held by the wall on the other side of said slot 93 and spring 9| tightens on shank 13 so that it cannot be turned. This construction prevents 5 undesired unrolling of exposed film on take up spool H.

A different embodiment shown in Fig. 4 discloses coiled spring 9| with portion 92 plus another portion 96 bent from portion 92 and ex- 10 tending parallel to the axis of the shank I3. When shank I3 is inserted into opening 74 in casing ll, portion 96 enters opening 91 in casing ll provided therefor. This construction functions the same in use as the other embodiment ll previously described.

Both of these constructions eliminate the need of a separate insert, may be more easily assembled and result in substantial economies.

While I have described portion 92 as on a 20 radius from the center of spring BI and portion 96 as extending parallel to the axis of the shank 13, yet I do not wish to be limited to this exact construction as these portions 92 and 96 may extend on any desired angle from the spring SI to fit within a suitable opening or slot placed therefor in the casing ll.

Having thus described my invention, I claim:

1. A turnable member for the film take up spool of a camera comprising a knob manually oper- $0 able from the exterior of the camera casing, said casing having an opening, a shank extending from said knob and through the opening in said casing, spring coiled around said shank adjacent the casing, said casing having a slot adjacent said 36 opening, said spring having an end extending on a radius from the center of the coil, said end being engaged in said slot so that as said knob is turned in the direction of the spring, said direction also being the same direction for winding g0 exposed film on the take up spool, the end of the spring contacts the wall of the casing to one side of said slot and permits the shank to rotate and upon the knob being turned in the other direction the end of the spring contacts the wall of the 45 casing on the other side of the slot so that the spring tightens on the shank and prevents turning.

2. A turnable member for the film take up spool of a camera comprising a knob manually 60 operable from the exterior of the camera casing, said casing having an opening, a shank extending from said knob and through the opening in said casing, a spring coiled around said shank adjacent the casing, said casing having a hole 56 being the same direction for winding exposed film on the take up spool, the end of the springcontacts the wall of the casing to one side of said hole and pennits the shank to rotate and upon the knob being turned in the other direction the end of the spring contacts the wall of the casing on the other side of the hole so that the spring tightens on the shank and prevents turning.

3. A turnable member for the film take up spool of a camera comprising a knob manually operable from the exterior of the camera casing, said casing having an opening, a shank extending from said knob and through the opening in said v casing, a spring having a coiled portionaround said shank adjacent the casing, said casing having an aperture adjacent said opening, said spring having an engaging portion, said engaging p01- 5 tion being engaged in said aperture so that as said knob is turned in the direction of the spring, said direction also being the same direction for winding exposed film on the take up spool, the

engaging portion' of the spring contacts the wall 10 of the casing to one side of said aperture and permits the shank to rotate. and upon the knob being turned in the other direction the engaging portion of the spring contacts the wall of the casing on the other side of the aperture so that 15 the spring tightens on the shank and prevents turning.

JACK GALTER. 

